Stop motion devices



Nov. 22, 1966 J. H. COULLIETTE 3,237,519

STOP MOTION DEVICES Filed May 12, 1964 q 2 h s ee l FIG.I

INVENTOR.

Nov. 22, 1966 n J. H. COULLIETTE STOP MOTION DEVICES 2 Sheets-Sheet 2 Filed May 12, 1964 d ///////////AI4 mm 6 B 5 4 5 m 1b m 7 1 4 Ill/ I l/fd A m wnw \A aw w 7/14/7471! 40 4 l lull v 2 FIG.4

FIG.3 Z AKW INVENTOR.

United States Patent F 3,287,519 STOP MOTION DEVICES James H. Coulliette, 4412 Alhambra Circle, Coral Gables, Fla. Filed May 12, 1964, Ser. No. 366,698 9 Claims. (Cl. 200-813) This invention rel-ates toa stop motion device, and more particularly to a device for detecting flaws in sheets of porous material as they are produced, and thereupon stopping a machine engaged in the production of said porous material as, for example, knitted fabrics.

It is another object of this invention to provide a sensitive device which will detect a small hole or a dropped stitch in a knitted fabric by means of differential air flow through adjacent areas of the fabric into symmetrical passages and actuate a control relay. 7

Another object of this invention is to provide a sensing device which utilizes the differential flow of fluid through a porous material to deflect a flexible vane and actuate a stop motion relay.

It is a further object of this invention to provide a sensing device which can detect holes in porous materials while making contact with only one side of the material.

Further objects and advantages of the invention will be apparent from the following description taken in conjunctionwith the drawings, wherein:

FIG. 1 is a view in perspective disclosing one modification of the invention.

FIG. 2 is a section taken along the lines AA of FIG. 1.

FIG. 3 is a section taken along the lines BB of FIG. 1.

FIG. 4 is a section taken along the lines CC of FIG. 1.

FIG. 5 is another embodiment of the passages 8, 9 and the septum 20 of FIG. 2.

FIG. 6 is one modification of a wiring diagram for the electrical control circuit.

Referring now to the drawings in more detail, the body 6 (FIG. 1) of the detector is formed from plastic or other suitable material. Said body 6 is mountedby suitable means on the frame of the machine engaged in forming the sheet 7 (FIGLZ) of porous material so that as said sheet 7 is formed it is caused to move under tension across apertures 8, 9 (FIG. 2) in the end 16 ofbody 6; said sheet 7 being in contact with surface 16 and effectively forming constrictions of the passages 3, 4 leading from apertures 8 and 9.

The symmetrical passages 3, 4 from apertures 8, 9 converge along the sides of septum 20 into parallel channels 11, 12 respectively. The dividing member between parallel channels 11, 12 comprises a thin flexible vane 10, said vane 10 having one end fixed in transverse bar member 13. Channels 11, 12 open into passages 24, 25 which diverge symmetrically past bar member 13, and merge into pipe 15. Said pipe 15 is attached to detector body 6 by screws 17, 17. Said pipe 15 is-connected to suitable pumping means whereby fluid is caused to flow through channels 11, 12 in said detector body 6.

The detecting means will operate with fluid pressure in channels 11, 12 either above or below the external pressure. However, in either embodiment the fluid stream 'must flow from apertures 8, 9 into channels 11, 12 respectively. FIG. 2 shows the arrangement when pipe 15 leads to an evacuating means. When said pipe 15 is connected to a compressor means, as is shown in dash lines in FIGURE 2, said pipe 15 must be attached to end 16 of detector body 6 instead of to end 18, and porous material 7 must contact end 18. In this regard it should be kept in mind that an important use of the herein disclosed device is on machines knitting tubular 3,287,519 Patented Nov. 22, 1966 fabric, and such knitting machines usually are so constructed that no fixed device can be located in contact with or closely adjacent to the exterior surface of the fabric tube which is being knitted. In such machines, the fabric tube is formed inside a head which revolves about a vertical axis, and the herein disclosed device is intended, in its entirety, to be located within said fabric tube. In such an arrangement, pipe 15 would have to be shifted to face surface 16 and the fabric 7 would be passed over surface 18 if pipe 15 were connected to a compressor discharge, and the fabric layer 7 would be held against surface 18 by virtue of the fact that it were being moved under tension across said surface.

It is quite obvious that, if the porous layer 7 were being processed in a machine which permitted having a fixed member proximate to the exterior surface of the porous layer, pipe 15 could be connected to a compressor and positioned to blow fluid through layer.7 and into openings, 8, 9. In other words, layer 7 would pass between pipe 15 and surface 16.

For simplicity further specification is written for the arrangement shown in FIG. 2 wherein the fluid stream is caused by an evacuating means to flow from the free end of vane 10 toward the fixed end of said vane 10. The mounting of vane 10 permits said vane 10 to bend as a cantilever beam when the fluid pressure in channel 12 is different from the pressure in channel 11.

A pair of electrical contact means 5, 5 (FIG. 3) is located in the outer wall of channel 12, and a second pair of contact means 14, 14 is similarly located in the outer wall of channel 11. When flexible vane 10 is formed of metal, and is flexed to touch contacts 5, 5 or 14, 14, the control electrical circuit is completed through relay coil 21 (FIG. 6).

The stop motion device of my invention is installed on a machine which produces porous sheet material, for example a knitted fabric, in such manner that the newly formed material passes over the face 16 of the detector device. The .detector device may, for example, be mounted inside the ring frame of a knitting machine producing a tubular fabric so that the face 16 of the detector device is in contact with the interior surface of the knitted fabric. The porous fabricserves to partially close, or constrict, the effective areas of apertures 8, 9 in face 16. Pipe 15 of the device is connected to a suitable pneumatic exhausting means which causes air to flow through the porous knitted fabric, through theapertures 8 and 9, into passages 3, 4, thence through channels 11' and 12 and into pipe 15.

Channels 11, 12 (FIG. 2) are symmetrical, having equal cross-sections when no air is. flowing through them, also when the areas of porous fabric covering aper-, tures 8 and 9 are of uniform porosity, the effective crosssections of apertures 8 and 9 are equal and the rates of air flow through channels 11 and 12 are equal. When a hole' or other change of porosity in the fabric crosses one of the apertures, aperture 8 for example, the rate of air flow through channel 11 is changed, and a resultant force acts upon the face of vane 10 and flexes said vane 10. This is in accord with the conservation of energy in the flow of fluids known as Bernoullis principle. When the result-ant force on vane 10 is sufiicient to bend said vane 10 into contact with electrical contact members 5, 5, the electrical control circuit (FIG. 6) is completed, relay 21 is energized, the contacts of relay 21 are opened, and motor 22 is stopped; signal light 23 is lighted, indicating to the operator that the machine is in need of attention.

In my invention the passages 3, 4 (FIG. 2) are designed in such manner that when vane 10 is deflected, its free end entering the air stream in channel 12, the air streams from apertures 8, 9 merge to form increased forces tending to push vane 10 against contacts 5, 5. The vane 10 3 will then be held against contacts 5, 5 until the air flow through the device is stopped. By reason of symmetry, when the direction of motion of the fabric is reversed, the passage of a flaw over aperture 9 will result in the flexing of vane to connect contacts 14, 14.

When corrosive fluids are caused to flow through the detector body 6, it is preferred to construct vane 10 of plastic or other corrosion resistant material and to replace contact members 5, 5 and 14, 14 by micro switches of which the push pin members protrude through the outer walls of body 6 into channels 11, 12.

When the detector is constructed with passages 3, 4 and septum 24 shaped as shown in FIG. 5, the electrical control circuit being completed by contact of metal vane 10 with metal septum 20, the device acts as a momentary switching means.

The sensitivity of my sensing device, i.e. the minimum change in eifective cross-section of aperture 8 (or 9) which will result in vane 10 completing the control circuit through contacts 5, 5 (or 14, 14) is a function of the air pressure differentials across apertures 8 and 9, the dimensions of channels 11, and 12, and the elastic properties of vane 10. To insure positive action, it is desirable to have the cross-sections of passages 24, 25 smaller than the cross sections of channels 11, 12 respectively.

This type of stop motion means will be of special value in the knitting of flat and tubular fabrics. The sensing head 6 may be placed adjacent to the knitting needles so that it scans the entire surface of the fabric as it is produced, and will detect a dropped stitch due to defective needle or broken yarn and stop the machine before the resulting run has extended more than one or two inches. This will markedly reduce the amount of waste fabric produced.

My invention is an improvement over devices comprising bellows or diaphragms actuated by the difference between a working air pressure and atmospheric pressure, which are necessarily sensitive to small changes in the working pressure. My device is insensitive to considerable variation in the working pressure which produces the fluid flow.

This stop motion device in any of its modified forms is economical and easy to produce. It will be apparent to those skilled in the art that various changes may be made in the invention, without departing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims. I claim:

1. A stop motion device constituted by a fluid actuated electrical switch which comprises: a body member, a

through passageway extending through said body member from one surface thereof to another, an electrical switching means comprising a movable vane extending axially along the length of said passageway and dividing a portion thereof into separate axial channels, spaced apart openings in said one surface leading into dilferent ones of said channels, fluid pumping means to induce a fluid flow through said passageway, said vane being movable in either of opposite directions in response to a flow differential in said channels, electrical contact means in each of said channels and spaced from said vane and actuable in accordance with the movements of said vane.

2. A stop motion device comprising a body member, a fluid conduit means extending through said member from a first opening means to a second opening means in the surface of said member, a vane extending longitudinally along said conduit means and thereby dividing at least a portion of said conduit means into separate channels said first opening means comprising spaced apart openings leading respectively into opposed ones of said channels, electrical contact means in each of said channels and spaced from said vane, said vane being movable in either of opposite directions toward either of said contacts in response to pressure differentials between fluid flowing through said channels, means to induce a fluid flow through said conduit means.

3. The stop motion device of claim 1, wherein said fluid pumping means comprises a vacuum source connected to said passageway at said other surface of said body member.

4. The stop motion device of claim 1, wherein said fluid pumping means comprises a pressure fluid source discharging into said openings in said one surface in said body member. 9

5. The stop motion device of claim 1, wherein said passageway comprises an elongate central conduit one end of which connects to separate inlet branches which in turn respectively connect with different ones of said openings in said one surface of said body member, said inlet branches respectively leading into different ones of said channels, the other end of said central conduit being connected to an opening in said other surface of said body member, said vane being cantileverically supported at one end of said central conduit and extending axially to substantially the opposite end of said central conduit.

6. The stop motion device of claim 5, wherein the free end of said vane is located at the end of said central conduit which connects to said branch conduits.

7. The stop motion device of claim 6, wherein said other end of said central conduit connects to separate outlet branches which respectively lead from different ones of said channels, the cross-sectional area of said outlet branches being smaller than that of said inlet branches.

8. The stop motion device of claim 1, wherein said fluid pumping means comprises gas pumping means.

9. The stop motion device of claim 1, wherein said fluid pumping means comprises a liquid pumping means.

References Cited by the Examiner UNITED STATES PATENTS 1,950,518 3/1934 Read 340259 2,853,574 9/1958 Quirk 200-81 2.900.468 9/1959 Joy 20081 X 2,953,654 9/ 1960 Bauder 20046 BERNARD A. GILHEANY, Primary Examiner. H. M. FLECK, G. I. MAIER, Assistant Examiners. 

1. A STOP MOTION DEVICE CONSTITUTED BY A FLUID ACTUATED ELECTRICAL SWITCH WHICH COMPRISES: A BODY MEMBER, A THROUGH PASSAGEWAY EXTENDING THROUGH SAID BODY MEMBER FROM ONE SURFACE THEREOF TO ANOTHER, AN ELECTRICAL SWITCHING MEANS COMPRISING A MOVABLE VANE EXTENDING AXIALLY ALONG THE LENGTH OF SAID PASSAGEWAY AND DIVIDING A PORTION THEREOF INTO SEPARATE AXIAL CHANNELS, SPACED APART OPENINGS IN SAID ONE SURFACE LEADING INTO DIFFERENT ONES OF SAID CHANNELS, FLUID PUMPING MEANS TO INDUCE A FLUID FLOW THROUGH SAID PASSAGEWAY, SAID VANE BEING MOVABLE IN EITHER OF OPPOSITE DIRECTIONS IN RESPONSE TO A FLOW DIFFERENTIAL IN SAID CHANNELS, ELECTRICAL CONTACT MEANS IN EACH OF SAID CHANNELS AND SPACED FROM SAID VANE AND ACTUATABLE IN ACCORDANCE WITH THE MOVEMENTS OF SAID VANE. 